Physical layer based mobility signaling

ABSTRACT

Aspects of the present disclosure provide a method for wireless communications by a user equipment (UE). The method generally includes receiving radio resource control (RRC) signaling indicating a set of cells that support physical (PHY) layer or medium access control (MAC) layer mobility signaling, receiving at least one downlink control information (DCI) indicating mobility information for the set of cells, and updating one or more features of the set of cells based on the DCI.

PRIORITY CLAIM(S)

This application claims benefit of and the priority to U.S. ProvisionalApplication No. 63/047,725, filed on Jul. 2, 2020, which is expresslyincorporated by reference in its entirety as if fully set forth belowand for all applicable purposes.

TECHNICAL FIELD

Aspects of the present disclosure relate to wireless communications, andmore particularly, to mobility techniques that allow for dynamicallyupdating a set of cells activated to serve a user equipment (UE), andassociated information, based on a downlink control information (DCI).

BACKGROUND

Wireless communication systems are widely deployed to provide varioustelecommunication services such as telephony, video, data, messaging,broadcasts, etc. These wireless communication systems may employmultiple-access technologies capable of supporting communication withmultiple users by sharing available system resources (e.g., bandwidth,transmit power, etc.). Examples of such multiple-access systems include3rd Generation Partnership Project (3GPP) Long Term Evolution (LTE)systems, LTE Advanced (LTE-A) systems, code division multiple access(CDMA) systems, time division multiple access (TDMA) systems, frequencydivision multiple access (FDMA) systems, orthogonal frequency divisionmultiple access (OFDMA) systems, single-carrier frequency divisionmultiple access (SC-FDMA) systems, and time division synchronous codedivision multiple access (TD-SCDMA) systems, to name a few.

These multiple access technologies have been adopted in varioustelecommunication standards to provide a common protocol that enablesdifferent wireless devices to communicate on a municipal, national,regional, and even global level. New radio (e.g., 5G NR) is an exampleof an emerging telecommunication standard. NR is a set of enhancementsto the LTE mobile standard promulgated by 3GPP. NR is designed to bettersupport mobile broadband Internet access by improving spectralefficiency, lowering costs, improving services, making use of newspectrum, and better integrating with other open standards using OFDMAwith a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL).To these ends, NR supports beamforming, multiple-input multiple-output(MIMO) antenna technology, and carrier aggregation.

However, as the demand for mobile broadband access continues toincrease, there exists a need for further improvements in NR and LTEtechnology. Preferably, these improvements should be applicable to othermulti-access technologies and the telecommunication standards thatemploy these technologies.

A control resource set (CORESET) for systems, such as an NR and LTEsystems, may comprise one or more control resource (e.g., time andfrequency resources) sets, configured for conveying PDCCH, within thesystem bandwidth. Within each CORESET, one or more search spaces (e.g.,common search space (CSS), UE-specific search space (USS), etc.) may bedefined for a given UE.

SUMMARY

The systems, methods, and devices of the disclosure each have severalinnovative aspects, no single one of which is solely responsible for thedesirable attributes.

Certain aspects of the present disclosure are directed to a method forwireless communication by a user equipment (UE). The method generallyincludes receiving radio resource control (RRC) signaling indicating aset of cells that support physical (PHY) layer or medium access control(MAC) layer mobility signaling, receiving at least one downlink controlinformation (DCI) indicating mobility information for the set of cells,and updating one or more features of the set of cells based on the DCI.

Certain aspects of the present disclosure are directed to a method forwireless communication by a network entity. The method generallyincludes sending a user equipment (UE) radio resource control (RRC)signaling indicating a set of cells that support physical (PHY) layer ormedium access control (MAC) layer mobility signaling, sending the UE atleast one downlink control information (DCI) indicating mobilityinformation for the set of cells, and communicating with the UE via asubset of the cells that are activated with one or more features of theset of cells updated based on the DCI.

Certain aspects of the present disclosure are directed to an apparatusfor wireless communication by a UE. The apparatus generally includes amemory and at least one processor coupled to the memory, the memory andthe at least one processor being configured to receive RRC signalingindicating a set of cells that support PHY layer or MAC layer mobilitysignaling, receive at least one DCI indicating mobility information forthe set of cells, and update one or more features of the set of cellsbased on the DCI.

Certain aspects of the present disclosure are directed to an apparatusfor wireless communication by a UE. The apparatus generally includesmeans for receiving RRC signaling indicating a set of cells that supportPHY layer or MAC layer mobility signaling, means for receiving at leastone DCI indicating mobility information for the set of cells, and meansfor updating one or more features of the set of cells based on the DCI.

Certain aspects of the present disclosure are directed to a computerreadable medium having instructions stored thereon for receiving RRCsignaling indicating a set of cells that support PHY layer or MAC layermobility signaling, receiving at least one DCI indicating mobilityinformation for the set of cells, and updating one or more features ofthe set of cells based on the DCI.

Certain aspects of the present disclosure are directed to a method forwireless communication by a network entity. The method generallyincludes sending a UE RRC signaling indicating a set of cells thatsupport PHY layer or MAC layer mobility signaling, sending the UE atleast one DCI indicating mobility information for the set of cells, andcommunicating with the UE via a subset of the cells that are activatedwith one or more features of the set of cells based on the DCI.

Certain aspects of the present disclosure are directed to an apparatusfor wireless communication by a network entity. The apparatus generallyincludes a memory and at least one processor coupled to the memory, thememory and the at least one processor being configured to send a UE RRCsignaling indicating a set of cells that support PHY layer or MAC layermobility signaling, send the UE at least one DCI indicating mobilityinformation for the set of cells, and communicate with the UE via asubset of the cells that are activated with one or more features of theset of cells based on the DCI.

Certain aspects of the present disclosure are directed to an apparatusfor wireless communication by a network entity. The apparatus generallyincludes means for sending a UE RRC signaling indicating a set of cellsthat support PHY layer or MAC layer mobility signaling, means forsending the UE at least one DCI indicating mobility information for theset of cells, and means for communicating with the UE via a subset ofthe cells that are activated with one or more features of the set ofcells based on the DCI.

Certain aspects of the present disclosure are directed to a computerreadable medium having instructions stored thereon for sending a UE RRCsignaling indicating a set of cells that support PHY layer or MAC layermobility signaling, sending the UE at least one DCI indicating mobilityinformation for the set of cells, and communicating with the UE via asubset of the cells that are activated with one or more features of theset of cells based on the DCI.

To the accomplishment of the foregoing and related ends, the one or moreaspects comprise the features hereinafter fully described andparticularly pointed out in the claims. The following description andthe appended drawings set forth in detail some illustrative features ofthe one or more aspects. These features are indicative, however, of buta few of the various ways in which the principles of various aspects maybe employed.

BRIEF DESCRIPTION OF THE DRAWINGS

Details of one or more implementations of the subject matter describedin this disclosure are set forth in the accompanying drawings and thedescription below. However, the accompanying drawings illustrate onlysome typical aspects of this disclosure and are therefore not to beconsidered limiting of its scope. Other features, aspects, andadvantages will become apparent from the description, the drawings andthe claims.

FIG. 1 shows an example wireless communication network in which someaspects of the present disclosure may be performed.

FIG. 2 shows a block diagram illustrating an example base station (BS)and an example user equipment (UE) in accordance with some aspects ofthe present disclosure.

FIG. 3A illustrates an example of a frame format for a telecommunicationsystem.

FIG. 3B illustrates how different synchronization signal blocks (SSBs)may be sent using different beams.

FIG. 4 illustrates an example architecture in which aspects of thepresent disclosure may be practiced.

FIGS. 5 and 6 illustrate example scenarios in which aspects of thepresent disclosure may be practiced.

FIGS. 7A and 7B illustrate an example of UE mobility, in accordance withsome aspects of the present disclosure.

FIG. 8 illustrates example operations for wireless communication by auser equipment (UE), in accordance with some aspects of the presentdisclosure.

FIG. 9 illustrates example operations for wireless communication by anetwork entity, in accordance with some aspects of the presentdisclosure.

FIG. 10A illustrates an example of a DCI selection of a cell, inaccordance with some aspects of the present disclosure.

FIG. 10B illustrates another example of DCI selection of a cell, inaccordance with some aspects of the present disclosure.

FIG. 11 illustrates an example of a DCI update of system information(SI), in accordance with some aspects of the present disclosure.

FIGS. 12 and 13 illustrate communications devices that may includevarious components configured to perform operations for the techniquesdisclosed herein in accordance with aspects of the present disclosure.

To facilitate understanding, identical reference numerals have beenused, where possible, to designate identical elements that are common tothe figures. It is contemplated that elements disclosed in one aspectmay be beneficially utilized on other aspects without specificrecitation.

DETAILED DESCRIPTION

Aspects of the present disclosure relate to wireless communications, andmore particularly, to mobility techniques that allow for dynamicallyupdating a set of cells and/or beams that are activated to serve a userequipment (UE). As will be described in greater detail below, the set ofactivated cells may be updated based on physical (PHY) layer (Layer1 orL1) signaling, such as via a DCI, that indicates one or more cells toactivate and/or de-activate. The DCI may also indicate an update tovarious cell-related information, such as system information.

The following description provides examples and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the scope of the disclosure. Various examples may omit,substitute, or add various procedures or components as appropriate. Forinstance, the methods described may be performed in an order differentfrom that described, and various steps may be added, omitted, orcombined. Also, features described with respect to some examples may becombined in some other examples. For example, an apparatus may beimplemented or a method may be practiced using any number of the aspectsset forth herein. In addition, the scope of the disclosure is intendedto cover such an apparatus or method which is practiced using otherstructure, functionality, or structure and functionality in addition to,or other than, the various aspects of the disclosure set forth herein.It should be understood that any aspect of the disclosure disclosedherein may be embodied by one or more elements of a claim.

In general, any number of wireless networks may be deployed in a givengeographic area. Each wireless network may support a particular radioaccess technology (RAT) and may operate on one or more frequencies. ARAT may also be referred to as a radio technology, an air interface,etc. A frequency may also be referred to as a carrier, a subcarrier, afrequency channel, a tone, a subband, etc. Each frequency may support asingle RAT in a given geographic area in order to avoid interferencebetween wireless networks of different RATs. In some cases, a 5G NR RATnetwork may be deployed.

FIG. 1 illustrates an example wireless communication network 100 inwhich aspects of the present disclosure may be performed. For example,as shown in FIG. 1, UE 120 a may include an L1/L2 mobility module 122that may be configured to perform (or cause UE 120 a to perform)operations 800 of FIG. 8. Similarly, a BS 110 a may include an L1/L2mobility module 112 that may be configured to perform (or cause BS 110 ato perform) operations 900 of FIG. 9.

NR access (e.g., 5G NR) may support various wireless communicationservices, such as enhanced mobile broadband (eMBB) targeting widebandwidth (e.g., 80 MHz or beyond), millimeter wave (mmWave) targetinghigh carrier frequency (e.g., 25 GHz or beyond), massive machine typecommunications MTC (mMTC) targeting non-backward compatible MTCtechniques, or mission critical services targeting ultra-reliablelow-latency communications (URLLC). These services may include latencyand reliability requirements. These services may also have differenttransmission time intervals (TTI) to meet respective quality of service(QoS) requirements. In addition, these services may co-exist in the sametime-domain resource (e.g., a slot or subframe) or frequency-domainresource (e.g., component carrier).

As illustrated in FIG. 1, the wireless communication network 100 mayinclude a number of base stations (BSs) 110 a-z (each also individuallyreferred to herein as BS 110 or collectively as BSs 110) and othernetwork entities. A BS 110 may provide communication coverage for aparticular geographic area, sometimes referred to as a “cell”, which maybe stationary or may move according to the location of a mobile BS 110.In some examples, the BSs 110 may be interconnected to one another or toone or more other BSs or network nodes (not shown) in wirelesscommunication network 100 through various types of backhaul interfaces(e.g., a direct physical connection, a wireless connection, a virtualnetwork, or the like) using any suitable transport network. In theexample shown in FIG. 1, the BSs 110 a, 110 b and 110 c may be macro BSsfor the macro cells 102 a, 102 b and 102 c, respectively. The BS 110 xmay be a pico BS for a pico cell 102 x. The BSs 110 y and 110 z may befemto BSs for the femto cells 102 y and 102 z, respectively. A BS maysupport one or multiple cells. The BSs 110 communicate with userequipment (UEs) 120 a-y (each also individually referred to herein as UE120 or collectively as UEs 120) in the wireless communication network100. The UEs 120 (e.g., 120 x, 120 y, etc.) may be dispersed throughoutthe wireless communication network 100, and each UE 120 may bestationary or mobile.

Wireless communication network 100 may also include relay stations(e.g., relay station 110 r), also referred to as relays or the like,that receive a transmission of data or other information from anupstream station (e.g., a BS 110 a or a UE 120 r) and sends atransmission of the data or other information to a downstream station(e.g., a UE 120 or a BS 110), or that relays transmissions between UEs120, to facilitate communication between devices.

A network controller 130 may couple to a set of BSs 110 and providecoordination and control for these BSs 110. The network controller 130may communicate with the BSs 110 via a backhaul. The BSs 110 may alsocommunicate with one another (e.g., directly or indirectly) via wirelessor wireline backhaul.

FIG. 2 shows a block diagram illustrating an example base station (BS)and an example user equipment (UE) in accordance with some aspects ofthe present disclosure.

At the BS 110, a transmit processor 220 may receive data from a datasource 212 and control information from a controller/processor 240. Thecontrol information may be for the physical broadcast channel (PBCH),physical control format indicator channel (PCFICH), physical hybrid ARQindicator channel (PHICH), physical downlink control channel (PDCCH),group common PDCCH (GC PDCCH), etc. The data may be for the physicaldownlink shared channel (PDSCH), etc. The processor 220 may process(e.g., encode and symbol map) the data and control information to obtaindata symbols and control symbols, respectively. The transmit processor220 may also generate reference symbols, such as for the primarysynchronization signal (PSS), secondary synchronization signal (SSS),and cell-specific reference signal (CRS). A transmit (TX) multiple-inputmultiple-output (MIMO) processor 230 may perform spatial processing(e.g., precoding) on the data symbols, the control symbols, or thereference symbols, if applicable, and may provide output symbol streamsto the modulators (MODs) 232 a-232 t. Each modulator 232 may process arespective output symbol stream (e.g., for OFDM, etc.) to obtain anoutput sample stream. Each modulator may further process (e.g., convertto analog, amplify, filter, and upconvert) the output sample stream toobtain a downlink signal. Downlink signals from modulators 232 a-232 tmay be transmitted via the antennas 234 a-234 t, respectively.

At the UE 120, the antennas 252 a-252 r may receive the downlink signalsfrom the BS 110 and may provide received signals to the demodulators(DEMODs) in transceivers 254 a-254 r, respectively. Each demodulator 254may condition (e.g., filter, amplify, downconvert, and digitize) arespective received signal to obtain input samples. Each demodulator mayfurther process the input samples (e.g., for OFDM, etc.) to obtainreceived symbols. A MIMO detector 256 may obtain received symbols fromall the demodulators 254 a-254 r, perform MIMO detection on the receivedsymbols if applicable, and provide detected symbols. A receive processor258 may process (e.g., demodulate, deinterleave, and decode) thedetected symbols, provide decoded data for the UE 120 to a data sink260, and provide decoded control information to a controller/processor280.

On the uplink, at UE 120, a transmit processor 264 may receive andprocess data (for example, for the physical uplink shared channel(PUSCH)) from a data source 262 and control information (for example,for the physical uplink control channel (PUCCH) from thecontroller/processor 280. The transmit processor 264 may also generatereference symbols for a reference signal (for example, for the soundingreference signal (SRS)). The symbols from the transmit processor 264 maybe precoded by a TX MIMO processor 266 if applicable, further processedby the demodulators in transceivers 254 a-254 r (for example, forSC-FDM, etc.), and transmitted to the BS 110. At the BS 110, the uplinksignals from the UE 120 may be received by the antennas 234, processedby the modulators 232, detected by a MIMO detector 236 if applicable,and further processed by a receive processor 238 to obtain decoded dataand control information sent by the UE 120. The receive processor 238may provide the decoded data to a data sink 239 and the decoded controlinformation to the controller/processor 240.

The memories 242 and 282 may store data and program codes for BS 110 andUE 120, respectively. A scheduler 244 may schedule UEs for datatransmission on the downlink or uplink.

The controller/processor 280 or other processors and modules at the UE120 may perform or direct the execution of processes for the techniquesdescribed herein. As shown in FIG. 2, the controller/processor 280 ofthe UE 120 has an L1/L2 mobility module 122 that may be configured toperform (or cause UE 120 to perform) operations 800 of FIG. 8.Similarly, the BS 110 a may include an L1/L2 mobility module 112 thatmay be configured to perform (or cause BS 110 a to perform) operations900 of FIG. 9.

FIG. 3A is a diagram showing an example of a frame format 300 for NR.The transmission timeline for each of the downlink and uplink may bepartitioned into units of radio frames. Each radio frame may have apredetermined duration (e.g., 10 ms) and may be partitioned into 10subframes, each of 1 ms, with indices of 0 through 9. Each subframe mayinclude a variable number of slots depending on the subcarrier spacing.Each slot may include a variable number of symbol periods (e.g., 7 or 14symbols) depending on the subcarrier spacing. The symbol periods in eachslot may be assigned indices. A mini-slot, which may be referred to as asub-slot structure, refers to a transmit time interval having a durationless than a slot (e.g., 2, 3, or 4 symbols).

Each symbol in a slot may indicate a link direction (e.g., DL, UL, orflexible) for data transmission and the link direction for each subframemay be dynamically switched. The link directions may be based on theslot format. Each slot may include DL/UL data as well as DL/UL controlinformation.

In NR, a synchronization signal (SS) block is transmitted. The SS blockincludes a PSS, a SSS, and a two symbol PBCH. The SS block can betransmitted in a fixed slot location, such as the symbols 0-3 as shownin FIG. 3A. The PSS and SSS may be used by UEs for cell search andacquisition. The PSS may provide half-frame timing, the SS may providethe CP length and frame timing. The PSS and SSS may provide the cellidentity. The PBCH carries some basic system information, such asdownlink system bandwidth, timing information within radio frame, SSburst set periodicity, system frame number, etc. The SS blocks may beorganized into SS bursts to support beam sweeping. Further systeminformation such as, remaining minimum system information (RMSI), systeminformation blocks (SIBs), other system information (OSI) can betransmitted on a physical downlink shared channel (PDSCH) in certainsubframes. The SS block can be transmitted up to sixty-four times, forexample, with up to sixty-four different beam directions for mmW. The upto sixty-four transmissions of the SS block are referred to as the SSburst set. SS blocks in an SS burst set are transmitted in the samefrequency region, while SS blocks in different SS bursts sets can betransmitted at different frequency locations.

As shown in FIG. 3B, the SS blocks may be organized into SS burst setsto support beam sweeping. As shown, each SSB within a burst set may betransmitted using a different beam, which may help a UE quickly acquireboth transmit (Tx) and receive (Rx) beams (particular for mmWapplications). A physical cell identity (PCI) may still decoded from thePSS and SSS of the SSB.

A control resource set (CORESET) for systems, such as an NR and LTEsystems, may comprise one or more control resource (e.g., time andfrequency resources) sets, configured for conveying PDCCH, within thesystem bandwidth. Within each CORESET, one or more search spaces (e.g.,common search space (CSS), UE-specific search space (USS), etc.) may bedefined for a given UE. According to aspects of the present disclosure,a CORESET is a set of time and frequency domain resources, defined inunits of resource element groups (REGs). Each REG may comprise a fixednumber (e.g., twelve) tones in one symbol period (e.g., a symbol periodof a slot), where one tone in one symbol period is referred to as aresource element (RE). A fixed number of REGs may be included in acontrol channel element (CCE). Sets of CCEs may be used to transmit newradio PDCCHs (NR-PDCCHs), with different numbers of CCEs in the setsused to transmit NR-PDCCHs using differing aggregation levels. Multiplesets of CCEs may be defined as search spaces for UEs, and thus a NodeBor other base station may transmit an NR-PDCCH to a UE by transmittingthe NR-PDCCH in a set of CCEs that is defined as a decoding candidatewithin a search space for the UE, and the UE may receive the NR-PDCCH bysearching in search spaces for the UE and decoding the NR-PDCCHtransmitted by the NodeB.

Example Methods for Physical Layer Based Mobility Signaling

Aspects of the present disclosure relate to wireless communications, andmore particularly, to mobility techniques that allow for dynamicallyupdating a set of cells and/or beams activated to serve a user equipment(UE). As will be described in greater detail below, the set of activatedcells may be updated based on physical (PHY) layer (Layer1 or L1) ormedium access control (MAC) layer (Layer2 or L2) signaling thatindicates one or more cells and/or beams to activate and/or de-activate.

The techniques presented herein may be applied in various bands utilizedfor new radio (NR). For example, for the higher band referred to asfrequency range (FR) 4 (e.g., 52.6 GHz-to 114.25 GHz), an orthogonalfrequency division multiplexed (OFDM) waveform with very largesubcarrier spacing (e.g. 960 kHz-to 3.84 MHz) is required to combatsevere phase noise. Due to the large subcarrier spacing, the slot lengthtends to be very short. In a lower band referred to as FR2 (24.25 GHz to52.6 GHz) with 120 kHz SCS, the slot length is 125p, while in FR4 with960 kHz, the slot length is 15.6p.

In multi-beam operation (e.g., involving FR1 and FR2 bands), moreefficient uplink/downlink beam management may allow for increasedintra-cell and inter-cell mobility (e.g., L1 and/or L2-centric mobility)and/or a larger number of transmission configuration indicator (TCI)states. For example, the TCI states may include the use of a common beamfor data and control transmission and reception for uplink and downlinkoperations, a unified TCI framework for uplink and downlink beamindication, and enhanced signaling mechanisms to improve latency andefficiency (e.g., dynamic usage of control signaling).

The techniques presented herein provide signaling mechanisms that mayhelp support such enhanced features, improve latency, and improveefficiency with more usage of dynamic control signaling. For example,the techniques described herein make use of physical layer (PHY, Layer1,or L1) or medium access control (MAC, Layer2 or L2) signaling, asopposed to higher layer (e.g., RRC) signaling.

FIG. 4 illustrates an example architecture in which aspects of thepresent disclosure may be practiced. As illustrated, the architectureincludes a gNB central unit (gNB-CU). The gNB-CU generally serves as alogical node hosting RRC, service data adaptation protocol (SDAP) andpacket data convergence protocol (PDCP) of the gNB that controls theoperation of one or more gNB distributed units (gNB-DUs). Asillustrated, the gNB-CU terminates an F1 interface connected with thegNB-DU.

A gNB-DU generally serves as a logical node hosting RLC, MAC and PHYlayers of the gNB, and its operation is controlled by gNB-CU. Asillustrated in FIGS. 5 and 6, one gNB-DU supports one or multiple cells(but each cell is supported by only one gNB-DU. The gNB-DU terminatesthe F1 interface connected with the gNB-CU.

FIGS. 5 and 6 illustrate example scenarios in which aspects of thepresent disclosure may be practiced.

As illustrated in FIG. 5, in some cases, a UE may be handed over between(source and target) cells supported by (radio units or RUs of) differentDUs under the same CU. The RUs generally contain only PHY layer logic.In the scenario of FIG. 5, the cells could have non-collocated (indifferent DUs) PHY, MAC, and RLC logic, but common PDCP and RRC logic(the same CU). While L1/L2 signaling techniques described herein may beused for mobility, the data path from PDCP to different RLCs presentsome control aspects that may be addressed by coordination between DUs.

In the scenario illustrated in FIG. 6, on the other hand, source andtarget cells are supported by (belong to) the same DU. Thus, L1/L2mobility may be particularly attractive in this scenario, as the cellscan share MAC and upper layers (same DU). In this scenario, whenperforming a handover via L1/L2 signaling, the data path at MAC andabove stays the same.

As noted above, the distributed RUs contain only PHY layer and may beused (activated/de-activated) in a similar manner to carrier aggregation(CA), but cells may be on the same carrier frequencies. As such, aspectsof the present disclosure, however, may utilize mechanisms similar tothose used in CA to enable L1/L2 mobility (e.g.,activating/de-activating cells to serve the UE).

As an initial step, RRC signaling may be used to configure a set ofcells for L1/L2 mobility. As an illustration, FIG. 7A shows an examplethat assumes a configured set of 8 cells (Cell1, Cell2, . . . , −8). Ingeneral, the cell set may be designed to be large enough to covermeaningful mobility (e.g., anticipated mobility of a UE within a givenarea and given time). As will be described below, mobility managementmay be performed by activating/de-activating cells in the set such thata subset of the cells are activated for serving the UE.

From the configured set, at any given time, a certain subset of cellsmay be activated for serving the UE. This set of activated cellsgenerally refers to one or more cells in the configured set that areactivated. If the set of activated cells includes two or more activatedcells, the UE may be handed over from one activated cell to anotheractivated cell via dynamic (PHY/MAC) signaling. In some cases, an activeset may contain only one cell, such that when signaling is received toactivate a new cell, the currently active serving cell may be put into adeactivated set. In other words, with such a scenario of active servingcell switching, there may be only one active serving cell at the time.

Referring again to FIG. 7A, the set of activated cells includes Cells2-4. In some cases cells which are activated for any given UE may dependon UE reported measurements. Configured cells that are not activated(e.g. a set of deactivated cells) may include the (remaining) group ofcells in in the configured set that are deactivated (not activated). InFIG. 7A, the set of deactivated cells includes Cell 1 and Cells 5-8.

Aspects of the present disclosure may provide for mobility within theactivated cells in the set of activated cells. In some cases, thesignaling mechanism may be relatively similar to beam management. Forexample, mobility management within the activated set may be performedthrough L1/L2 signaling used to activate/deactivate cells in theactivated and set of deactivated cells to select beams within theactivated cells.

As illustrated in FIG. 7B, as the UE moves, cells from the set aredeactivated and activated, for example, based on signal quality(measurements reported by the UE) and other considerations (e.g.,loading of the cells). In the example shown in FIG. 9B, as the UE movesfrom left (at time t1) to right (at time t2), cell 5 (which is nowcloser) is activated and cell 2 (which is now farther) is de-activated.Thus, after the move, the set of activated cells includes Cell3, Cell4,and Cell5.

The cells that are activated/deactivated by L1/L2 signaling may be basedon network control, UE recommendation, and/or a UE decision. In general,the L1/L2 signaling (e.g., DCI and/or MAC-CEs) could carry activationand/or deactivation commands (e.g., that indicate cells to be activatedand cells to be deactivated).

If a UE is capable of supporting only one activated cell at a time, anactivation command indicating a new cell could implicitly deactivate acurrently active cell (e.g. upon UE acknowledging the command). As notedabove, in the case of the active set containing only one cell, whensignaling is received to activate a new cell, the currently activeserving cell may be put into deactivated set.

Aspects of the present disclosure may provide for mobility within a setof cells using physical layer (L1) mobility signaling.

FIG. 8 illustrates example operations 800 that may be performed by a UEto identify an initial beam to use in communicating with a selected cellin L1-based mobility, in accordance with certain aspects of the presentdisclosure. Operations 800 may be performed, for example, by a UE 120illustrated in FIG. 1.

Operations 800 begin, at 802, by receiving RRC signaling indicating aset of cells that support PHY layer or MAC layer mobility signaling. Forexample, the UE may be configured, via RRC signaling, with a set ofcells that support physical layer mobility, as shown in the examples ofFIGS. 7A and 7B.

At 804, the UE receives at least one downlink control information (DCI)indicating mobility information for the set of cells. At 806, the UEupdates one or more features of the set of cells based on the DCI. Forexample, as shown in FIGS. 10A and 10B, the DCI may indicate one or moreof the configured cells to activate or deactivate. As another example,as shown in FIG. 11, the DCI may select a set of system information (SI)values, from different sets preconfigured via RRC signaling.

FIG. 9 illustrates example operations 900 that may consideredcomplementary to operations 800 of FIG. 8. For example, operations 900may be performed by a network entity (e.g., a gNB DU/CU) to dynamicallyactivate cells and select beams to support mobility of a UE (performingoperations 800 of FIG. 8).

Operations 900 begin, at 902, by sending a UE radio resource control(RRC) signaling indicating a set of cells that support PHY layer or MAClayer mobility signaling. At 904, the network entity sends the UE atleast one DCI indicating mobility information for the set of cells. At906, the network entity communicates with the UE via a subset of thecells that are activated with one or more features of the set of cellsupdated based on the DCI.

Operations 800 and 900 of FIGS. 8 and 9 may be further understood withreference to FIGS. 10A, 10B and 11 which illustrate examples ofDCI-based mobility signaling, in accordance with aspects of the presentdisclosure.

As illustrated in FIGS. 10A and 10B, in some cases, a new DCI format mayconvey at least the ID information of the cell to be activated and/ordeactivated from the configured cell set.

As illustrated in FIG. 10A, the DCI may include a field (e.g.,Cell_ID_Select) with one or more bits that serve as a pointer to one ofthe cell IDs of the set of cells configured by RRC. Continuing with theexample shown in FIGS. 7A and 7B, assuming the configured set has 8cells, a 3-bit field may be used to indicate one of the cells to beactivated or deactivated. The DCI shown in FIG. 10A, for example, mayhave been received by the UE of FIG. 7B at time t2 to activate Cell ID5. In some cases, an extra bit may indicate whether the identified cellis activated or de-activated or the indication could be implicit (e.g.,if the identified cell is not activated, the UE may implicitly determinethe DCI is for activation).

As illustrated in FIG. 10B, the DCI may include a bitmap, where each bitcorresponds to one of the cell IDs of the set of cells configured byRRC. While the bitmap represents additional overhead relative to theselection field of FIG. 10A, one advantage is the bitmap may be able toindicate multiple cells to be activated and/or deactivated. In theillustrated example, a value of 1 in the bitmap indicates acorresponding cell to be activated (or to maintain in an activatedstate), while a value of 0 in the bitmap indicates a corresponding cellto be deactivated (or to maintain in a deactivated state).

As illustrated in FIG. 11, in some cases, a DCI with mobility signalingcould be used to update System Information (SI) for one or more of thecells in the set. In the illustrated example, the DCI may have a fieldthat is used to activate or deactivate a set of SI values, fromdifferent sets of SI values preconfigured via RRC signaling.

In some cases, SI information elements (IEs) that are eligible forupdate (e.g. via physical layer signaling) may be arranged in apredefined order (when configured). This may allow those IEs to beaddressed, for example, based on numbering or via a bitmap in the DCI.

In addition or as an alternative, DCI could activate some other RRCpreconfigured options for one or more cells at their activation. Forexample, the options may relate a timing advance group (TAG) timingadvance (TA) information, a measurement configuration, and/or an updateor change to a primary cell (PCell). In this manner, preconfiguredoptions desired for a cell may be activated when that cell is activated.

In some cases, the DCI (or DCIs) for mobility signaling could carry onekind of information or be designed to carry multiple kinds ofinformation in the context of (L1/L2) mobility for the cells in theconfigured set. For example, one DCI type may allow for SI updates,while another type of DCI may allow for measurements and TAG informationchanges.

In some cases, if a larger payload is required, a two-stage DCI may beused. In such cases, a first DCI could specify what kind of the info isprovided in a second DCI.

For reliability, it may be desirable that the UE acknowledge the DCI. Inother words, rather than waiting to acknowledge an actual transmissionscheduled by the DCI, in this case, the UE acknowledges the DCI itself,allowing the network to know the UE received the corresponding update tothe cells. In some cases, the updates may not be applied until theacknowledgment is received.

In some cases, the L2-based signaling described herein could be combinedwith L1-based signaling. This may involve, for example, by activating asubset of cells via L2 signaling and indicating mobility information(e.g., activation/de-activation and/or updating corresponding features)within the subset via downlink control information (DCI).

Example Communications Devices

FIG. 12 illustrates a communications device 1200 that may includevarious components (e.g., corresponding to means-plus-functioncomponents) configured to perform operations for the techniquesdisclosed herein, such as the operations illustrated in FIG. 8. Thecommunications device 1200 includes a processing system 1202 coupled toa transceiver 1208. The transceiver 1208 is configured to transmit andreceive signals for the communications device 1200 via an antenna 1210,such as the various signals as described herein. The processing system1202 may be configured to perform processing functions for thecommunications device 1200, including processing signals received and/orto be transmitted by the communications device 1200.

The processing system 1202 includes a processor 1204 coupled to acomputer-readable medium/memory 1212 via a bus 1206. In certain aspects,the computer-readable medium/memory 1212 is configured to storeinstructions (e.g., computer-executable code) that when executed by theprocessor 1204, cause the processor 1204 to perform the operationsillustrated in FIG. 8, or other operations for performing the varioustechniques discussed herein. In certain aspects, computer-readablemedium/memory 1212 stores code 1214 for receiving radio resource control(RRC) signaling indicating a set of cells that support physical (PHY)layer or medium access control (MAC) layer mobility signaling; code 1216for receiving at least one DCI indicating mobility information for theset of cells; and code 1218 for updating one or more features of the setof cells based on the DCI. In certain aspects, the processor 1204 hascircuitry configured to implement the code stored in thecomputer-readable medium/memory 1212. The processor 1204 includescircuitry 1220 for receiving RRC signaling indicating a set of cellsthat support PHY layer or MAC layer mobility signaling; circuitry 1222for receiving at least one DCI indicating mobility information for theset of cells; and circuitry 1224 for updating one or more features ofthe set of cells based on the DCI.

FIG. 13 illustrates a communications device 1300 that may includevarious components (e.g., corresponding to means-plus-functioncomponents) configured to perform operations for the techniquesdisclosed herein, such as the operations illustrated in FIG. 9. Thecommunications device 1300 includes a processing system 1302 coupled toa transceiver 1308. The transceiver 1308 is configured to transmit andreceive signals for the communications device 1300 via an antenna 1310,such as the various signals as described herein. The processing system1302 may be configured to perform processing functions for thecommunications device 1300, including processing signals received and/orto be transmitted by the communications device 1300.

The processing system 1302 includes a processor 1304 coupled to acomputer-readable medium/memory 1312 via a bus 1306. In certain aspects,the computer-readable medium/memory 1312 is configured to storeinstructions (e.g., computer-executable code) that when executed by theprocessor 1304, cause the processor 1304 to perform the operationsillustrated in FIG. 9, or other operations for performing the varioustechniques discussed herein. In certain aspects, computer-readablemedium/memory 1312 stores code 1314 for sending a UE RRC signalingindicating a set of cells that support PHY layer or MAC layer mobilitysignaling; code 1316 for sending the UE at least one DCI indicatingmobility information for the set of cells; and code 1318 forcommunicating with the UE via a subset of the cells that are activatedwith one or more features of the set of cells based on the DCI. Incertain aspects, the processor 1304 has circuitry configured toimplement the code stored in the computer-readable medium/memory 1312.The processor 1304 includes circuitry 1320 for sending a UE RRCsignaling indicating a set of cells that support PHY layer or MAC layermobility signaling; circuitry 1322 for sending the UE at least one DCIindicating mobility information for the set of cells; and circuitry 1324for communicating with the UE via a subset of the cells that areactivated with one or more features of the set of cells based on theDCI.

Example Aspects

Aspect 1: A method for wireless communications by a user equipment (UE),comprising receiving radio resource control (RRC) signaling indicating aset of cells that support physical (PHY) layer or medium access control(MAC) layer mobility signaling, receiving at least one downlink controlinformation (DCI) indicating mobility information for the set of cells,and updating one or more features of the set of cells based on the DCI.

Aspect 2: The method of Aspect 1, wherein the set of cells are supportedby one or more distributed units (DUs) under a common central unit (CU).

Aspect 3: The method of Aspect 2, wherein the one or more DUs comprisesa common DU that supports each cell of the set of cells.

Aspect 4: The method of any of Aspects 1-3, wherein the DCI indicates atleast one of an identifier (ID) of a cell to be activated that is notcurrently in the subset of cells activated for serving the UE or an IDof one of the cells in the subset of cells that is to be de-activated.

Aspect 5: The method of Aspect 4, wherein the DCI comprises a field thatpoints to the ID of the cell to be activated or deactivated in a tableor list configured by the RRC signaling.

Aspect 6: The method of any of Aspects 1-5, wherein the DCI indicates anupdate to System Information (SI) for one or more of the cells in theset.

Aspect 7: The method of Aspect 6, wherein the RRC signaling configuresone or more sets of SI values and the DCI indicates the update to SI byat least one of deactivating or activating one or more of the sets of SIvalues.

Aspect 8: The method of any of Aspects 1-7, wherein one or more SIinformation elements (IEs) eligible for updating via the DCI occur in apredefined order and are addressed based on at least one of numbering ora bitmap in the DCI.

Aspect 9: The method of any of Aspects 1-8, wherein the RRC signalingindicates one or more sets of options for cells in the set and the DCIactivates one or more sets of options for a cell upon activation.

Aspect 10: The method of Aspect 9, wherein at least some of the optionsrelate to: a timing advance group (TAG) timing advance (TA) information,a measurement configuration, or and update or change to a primary cell(PCell).

Aspect 11: The method of any of Aspects 1-10, wherein a format of theDCI depends, at least in part, on a type or types of informationconveyed.

Aspect 12: The method of any of Aspects 1-11, wherein the at least oneDCI comprises at least a first DCI and a second DCI and the first DCIindicates a type or types of information provided in the second DCI.

Aspect 13: The method of any of Aspects 1-12, further comprisingtransmitting an acknowledgment of the at least one DCI.

Aspect 14: A method for wireless communications by a network entity,comprising sending a user equipment (UE) radio resource control (RRC)signaling indicating a set of cells that support physical (PHY) layer ormedium access control (MAC) layer mobility signaling, sending the UE atleast one downlink control information (DCI) indicating mobilityinformation for the set of cells, and communicating with the UE via asubset of the cells that are activated with one or more features of theset of cells updated based on the DCI.

Aspect 15: The method of Aspect 14, wherein the set of cells aresupported by one or more distributed units (DUs) under a common centralunit (CU).

Aspect 16: The method of Aspect 15, wherein the one or more DUscomprises a common DU that supports each cell of the set of cells.

Aspect 17: The method of any of Aspects 14-16, wherein the DCI indicatesat least one of an identifier (ID) of a cell to be activated that is notcurrently in the subset of cells activated for serving the UE or an IDof one of the cells in the subset of cells that is to be de-activated.

Aspect 18: The method of Aspect 17, wherein the DCI comprises a fieldthat points to the ID of the cell to be activated or deactivated in atable or list configured by the RRC signaling.

Aspect 19: The method of Aspects 14-18, wherein the DCI indicates anupdate to System Information (SI) for one or more of the cells in theset.

Aspect 20: The method of Aspect 19, wherein the RRC signaling configuresone or more sets of SI values and the DCI indicates the update to SI byat least one of deactivating or activating one or more of the sets of SIvalues.

Aspect 21: The method of Aspects 14-20, wherein one or more SIinformation elements (IEs) eligible for updating via the DCI occur in apredefined order and are addressed based on at least one of numbering ora bitmap in the DCI.

Aspect 22: The method of Aspects 14-21, wherein the RRC signalingindicates one or more sets of options for cells in the set and the DCIactivates one or more sets of options for a cell upon activation.

Aspect 23: The method of Aspect 22, wherein at least some of the optionsrelate to: a timing advance group (TAG) timing advance (TA) information,a measurement configuration, or and update or change to a primary cell(PCell).

Aspect 24: The method of Aspects 14-23, wherein a format of the DCIdepends, at least in part, on a type or types of information conveyed.

Aspect 25: The method of Aspects 14-24, wherein the at least one DCIcomprises at least a first DCI and a second DCI and the first DCIindicates a type or types of information provided in the second DCI.

Aspect 26: The method of Aspects 14-25, further comprising receiving,from the UE, an acknowledgment of the at least one DCI and updating theone or more features of the set of cells only after receiving theacknowledgment.

Aspect 27: An apparatus for wireless communications by a user equipment(UE), comprising means for receiving radio resource control (RRC)signaling indicating a set of cells that support physical (PHY) layer ormedium access control (MAC) layer mobility signaling, means forreceiving at least one downlink control information (DCI) indicatingmobility information for the set of cells, and means for updating one ormore features of the set of cells based on the DCI.

Aspect 28: An apparatus for wireless communications by a network entity,comprising means for sending a user equipment (UE) radio resourcecontrol (RRC) signaling indicating a set of cells that support physical(PHY) layer or medium access control (MAC) layer mobility signaling,means for sending the UE at least one downlink control information (DCI)indicating mobility information for the set of cells, and means forcommunicating with the UE via a subset of the cells that are activatedwith one or more features of the set of cells updated based on the DCI.

Aspect 29: An apparatus for wireless communications by a user equipment(UE), comprising a receiver configured to receive radio resource control(RRC) signaling indicating a set of cells that support physical (PHY)layer or medium access control (MAC) layer mobility signaling andreceive at least one downlink control information (DCI) indicatingmobility information for the set of cells and at least one processorconfigured to update one or more features of the set of cells based onthe DCI.

Aspect 30: An apparatus for wireless communications by a network entity,comprising a transmitter configured to send a user equipment (UE) radioresource control (RRC) signaling indicating a set of cells that supportphysical (PHY) layer or medium access control (MAC) layer mobilitysignaling and to send the UE at least one downlink control information(DCI) indicating mobility information for the set of cells and at leastone processor configured to communicate with the UE via a subset of thecells that are activated with one or more features of the set of cellsupdated based on the DCI.

The techniques described herein may be used for various wirelesscommunication technologies, such as NR (e.g., 5G NR), 3GPP Long TermEvolution (LTE), LTE-Advanced (LTE-A), code division multiple access(CDMA), time division multiple access (TDMA), frequency divisionmultiple access (FDMA), orthogonal frequency division multiple access(OFDMA), single-carrier frequency division multiple access (SC-FDMA),time division synchronous code division multiple access (TD-SCDMA), andother networks. The terms “network” and “system” are often usedinterchangeably. A CDMA network may implement a radio technology such asUniversal Terrestrial Radio Access (UTRA), cdma2000, etc. UTRA includesWideband CDMA (WCDMA) and other variants of CDMA. cdma2000 coversIS-2000, IS-95 and IS-856 standards. A TDMA network may implement aradio technology such as Global System for Mobile Communications (GSM).An OFDMA network may implement a radio technology such as NR (e.g. 5GRA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11(Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA andE-UTRA are part of Universal Mobile Telecommunication System (UMTS). LTEand LTE-A are releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE,LTE-A and GSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). cdma2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). NR is an emerging wireless communications technologyunder development.

The techniques described herein may be used for the wireless networksand radio technologies mentioned above as well as other wirelessnetworks and radio technologies. For clarity, while aspects may bedescribed herein using terminology commonly associated with 3G, 4G, or5G wireless technologies, aspects of the present disclosure can beapplied in other generation-based communication systems.

In 3GPP, the term “cell” can refer to a coverage area of a Node B (NB)or a NB subsystem serving this coverage area, depending on the contextin which the term is used. In NR systems, the term “cell” and BS, nextgeneration NodeB (gNB or gNodeB), access point (AP), distributed unit(DU), carrier, or transmission reception point (TRP) may be usedinterchangeably. A BS may provide communication coverage for a macrocell, a pico cell, a femto cell, or other types of cells. A macro cellmay cover a relatively large geographic area (e.g., several kilometersin radius) and may allow unrestricted access by UEs with servicesubscription. A pico cell may cover a relatively small geographic areaand may allow unrestricted access by UEs with service subscription. Afemto cell may cover a relatively small geographic area (for example, ahome) and may allow restricted access by UEs having an association withthe femto cell (e.g., UEs in a Closed Subscriber Group (CSG), UEs forusers in the home, etc.). A BS for a macro cell may be referred to as amacro BS. A BS for a pico cell may be referred to as a pico BS. ABS fora femto cell may be referred to as a femto BS or a home BS.

A UE may also be referred to as a mobile station, a terminal, an accessterminal, a subscriber unit, a station, a Customer Premises Equipment(CPE), a cellular phone, a smart phone, a personal digital assistant(PDA), a wireless modem, a wireless communication device, a handhelddevice, a laptop computer, a cordless phone, a wireless local loop (WLL)station, a tablet computer, a camera, a gaming device, a netbook, asmartbook, an ultrabook, an appliance, a medical device or medicalequipment, a biometric sensor/device, a wearable device such as a smartwatch, smart clothing, smart glasses, a smart wrist band, smart jewelry(e.g., a smart ring, a smart bracelet, etc.), an entertainment device(e.g., a music device, a video device, a satellite radio, etc.), avehicular component or sensor, a smart meter/sensor, industrialmanufacturing equipment, a global positioning system device, or anyother suitable device that is configured to communicate via a wirelessor wired medium. Some UEs may be considered machine-type communication(MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include,for example, robots, drones, remote devices, sensors, meters, monitors,location tags, etc., that may communicate with a BS, another device(e.g., remote device), or some other entity. A wireless node mayprovide, for example, connectivity for or to a network (e.g., a widearea network such as Internet or a cellular network) via a wired orwireless communication link. Some UEs may be consideredInternet-of-Things (IoT) devices, which may be narrowband IoT (NB-IoT)devices.

Some wireless networks (e.g., LTE) utilize orthogonal frequency divisionmultiplexing (OFDM) on the downlink and single-carrier frequencydivision multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM partitionthe system bandwidth into multiple (K) orthogonal subcarriers, which arealso commonly referred to as tones, bins, etc. Each subcarrier may bemodulated with data. In general, modulation symbols are sent in thefrequency domain with OFDM and in the time domain with SC-FDM. Thespacing between adjacent subcarriers may be fixed, and the total numberof subcarriers (K) may be dependent on the system bandwidth. Forexample, the spacing of the subcarriers may be 15 kHz and the minimumresource allocation (called a “resource block” (RB)) may be 12subcarriers (or 180 kHz). Consequently, the nominal Fast FourierTransfer (FFT) size may be equal to 128, 256, 512, 1024 or 2048 forsystem bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz),respectively. The system bandwidth may also be partitioned intosubbands. For example, a subband may cover 1.08 MHz (e.g., 6 RBs), andthere may be 1, 2, 4, 8, or 16 subbands for system bandwidth of 1.25,2.5, 5, 10 or 20 MHz, respectively. In LTE, the basic transmission timeinterval (TTI) or packet duration is the 1 ms subframe.

NR may utilize OFDM with a CP on the uplink and downlink and includesupport for half-duplex operation using TDD. In NR, a subframe is still1 ms, but the basic TTI is referred to as a slot. A subframe contains avariable number of slots (e.g., 1, 2, 4, 8, 16, . . . slots) dependingon the subcarrier spacing. The NR RB is 12 consecutive frequencysubcarriers. NR may support a base subcarrier spacing of 15 KHz andother subcarrier spacing may be defined with respect to the basesubcarrier spacing, for example, 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc.The symbol and slot lengths scale with the subcarrier spacing. The CPlength also depends on the subcarrier spacing. Beamforming may besupported and beam direction may be dynamically configured. MIMOtransmissions with precoding may also be supported. In some examples,MIMO configurations in the DL may support up to 8 transmit antennas withmulti-layer DL transmissions up to 8 streams and up to 2 streams per UE.In some examples, multi-layer transmissions with up to 2 streams per UEmay be supported. Aggregation of multiple cells may be supported with upto 8 serving cells.

In some examples, access to the air interface may be scheduled. Ascheduling entity (e.g., a BS) allocates resources for communicationamong some or all devices and equipment within its service area or cell.The scheduling entity may be responsible for scheduling, assigning,reconfiguring, and releasing resources for one or more subordinateentities. That is, for scheduled communication, subordinate entitiesutilize resources allocated by the scheduling entity. Base stations arenot the only entities that may function as a scheduling entity. In someexamples, a UE may function as a scheduling entity and may scheduleresources for one or more subordinate entities (e.g., one or more otherUEs), and the other UEs may utilize the resources scheduled by the UEfor wireless communication. In some examples, a UE may function as ascheduling entity in a peer-to-peer (P2P) network, or in a mesh network.In a mesh network example, UEs may communicate directly with one anotherin addition to communicating with a scheduling entity.

As used herein, the term “determining” may encompass one or more of awide variety of actions. For example, “determining” may includecalculating, computing, processing, deriving, investigating, looking up(e.g., looking up in a table, a database or another data structure),assuming and the like. Also, “determining” may include receiving (e.g.,receiving information), accessing (e.g., accessing data in a memory) andthe like. Also, “determining” may include resolving, selecting,choosing, establishing and the like.

As used herein, “or” is used intended to be interpreted in the inclusivesense, unless otherwise explicitly indicated. For example, “a or b” mayinclude a only, b only, or a combination of a and b. As used herein, aphrase referring to “at least one of” or “one or more of” a list ofitems refers to any combination of those items, including singlemembers. For example, “at least one of: a, b, or c” is intended to coverthe possibilities of: a only, b only, c only, a combination of a and b,a combination of a and c, a combination of b and c, and a combination ofa and b and c.

The various operations of methods described above may be performed byany suitable means capable of performing the corresponding functions.The means may include various hardware and/or software component(s)and/or module(s), including, but not limited to a circuit, anapplication specific integrated circuit (ASIC), or processor. Generally,where there are operations illustrated in figures, those operations mayhave corresponding counterpart means-plus-function components. Forexample, various operations shown in FIGS. 8 and 9 may be performed byvarious processors shown in FIG. 2.

The various illustrative logical blocks, modules and circuits describedin connection with the present disclosure may be implemented orperformed with a general purpose processor, a digital signal processor(DSP), an application specific integrated circuit (ASIC), a fieldprogrammable gate array (FPGA) or other programmable logic device (PLD),discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general-purpose processor may be a microprocessor, but in thealternative, the processor may be any commercially available processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

If implemented in hardware, an example hardware configuration maycomprise a processing system in a wireless node. The processing systemmay be implemented with a bus architecture. The bus may include anynumber of interconnecting buses and bridges depending on the specificapplication of the processing system and the overall design constraints.The bus may link together various circuits including a processor,machine-readable media, and a bus interface. The bus interface may beused to connect a network adapter, among other things, to the processingsystem via the bus. The network adapter may be used to implement thesignal processing functions of the PHY layer. In the case of a UE 120(see FIG. 1), a user interface (e.g., keypad, display, mouse, joystick,etc.) may also be connected to the bus. The bus may also link variousother circuits such as timing sources, peripherals, voltage regulators,power management circuits, and the like, which are well known in theart, and therefore, will not be described any further. The processor maybe implemented with one or more general-purpose and/or special-purposeprocessors. Examples include microprocessors, microcontrollers, DSPprocessors, and other circuitry that can execute software. Those skilledin the art will recognize how best to implement the describedfunctionality for the processing system depending on the particularapplication and the overall design constraints imposed on the overallsystem.

If implemented in software, the functions may be stored or transmittedover as one or more instructions or code on a computer readable medium.Software shall be construed broadly to mean instructions, data, or anycombination thereof, whether referred to as software, firmware,middleware, microcode, hardware description language, or otherwise.Computer-readable media include both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. The processor may beresponsible for managing the bus and general processing, including theexecution of software modules stored on the machine-readable storagemedia. A computer-readable storage medium may be coupled to a processorsuch that the processor can read information from, and write informationto, the storage medium. In the alternative, the storage medium may beintegral to the processor. By way of example, the machine-readable mediamay include a transmission line, a carrier wave modulated by data,and/or a computer readable storage medium with instructions storedthereon separate from the wireless node, all of which may be accessed bythe processor through the bus interface. Alternatively, or in addition,the machine-readable media, or any portion thereof, may be integratedinto the processor, such as the case may be with cache and/or generalregister files. Examples of machine-readable storage media may include,by way of example, RAM (Random Access Memory), flash memory, ROM (ReadOnly Memory), PROM (Programmable Read-Only Memory), EPROM (ErasableProgrammable Read-Only Memory), EEPROM (Electrically ErasableProgrammable Read-Only Memory), registers, magnetic disks, opticaldisks, hard drives, or any other suitable storage medium, or anycombination thereof. The machine-readable media may be embodied in acomputer-program product.

A software module may comprise a single instruction, or manyinstructions, and may be distributed over several different codesegments, among different programs, and across multiple storage media.The computer-readable media may comprise a number of software modules.The software modules include instructions that, when executed by anapparatus such as a processor, cause the processing system to performvarious functions. The software modules may include a transmissionmodule and a receiving module. Each software module may reside in asingle storage device or be distributed across multiple storage devices.By way of example, a software module may be loaded into RAM from a harddrive when a triggering event occurs. During execution of the softwaremodule, the processor may load some of the instructions into cache toincrease access speed. One or more cache lines may then be loaded into ageneral register file for execution by the processor. When referring tothe functionality of a software module below, it will be understood thatsuch functionality is implemented by the processor when executinginstructions from that software module.

Also, any connection is properly termed a computer-readable medium. Forexample, if the software is transmitted from a website, server, or otherremote source using a coaxial cable, fiber optic cable, twisted pair,digital subscriber line (DSL), or wireless technologies such as infrared(IR), radio, and microwave, then the coaxial cable, fiber optic cable,twisted pair, DSL, or wireless technologies such as infrared, radio, andmicrowave are included in the definition of medium. Disk and disc, asused herein, include compact disc (CD), laser disc, optical disc,digital versatile disc (DVD), floppy disk, and Blu-ray® disc where disksusually reproduce data magnetically, while discs reproduce dataoptically with lasers. Thus, in some aspects computer-readable media maycomprise non-transitory computer-readable media (e.g., tangible media).In addition, for other aspects computer-readable media may comprisetransitory computer-readable media (e.g., a signal). Combinations of theabove should also be included within the scope of computer-readablemedia.

Thus, certain aspects may comprise a computer program product forperforming the operations presented herein. For example, such a computerprogram product may comprise a computer-readable medium havinginstructions stored (and/or encoded) thereon, the instructions beingexecutable by one or more processors to perform the operations describedherein. For example, instructions for performing the operationsdescribed herein and illustrated in FIGS. 8 and 9.

Various modifications to the implementations described in thisdisclosure may be readily apparent to persons having ordinary skill inthe art, and the generic principles defined herein may be applied toother implementations without departing from the spirit or scope of thisdisclosure. Thus, the claims are not intended to be limited to theimplementations shown herein, but are to be accorded the widest scopeconsistent with this disclosure, the principles and the novel featuresdisclosed herein.

Additionally, various features that are described in this specificationin the context of separate implementations also can be implemented incombination in a single implementation. Conversely, various featuresthat are described in the context of a single implementation also can beimplemented in multiple implementations separately or in any suitablesubcombination. As such, although features may be described above asacting in particular combinations, and even initially claimed as such,one or more features from a claimed combination can in some cases beexcised from the combination, and the claimed combination may bedirected to a subcombination or variation of a subcombination.

Similarly, while operations are depicted in the drawings in a particularorder, this should not be understood as requiring that such operationsbe performed in the particular order shown or in sequential order, orthat all illustrated operations be performed, to achieve desirableresults. Further, the drawings may schematically depict one or moreexample processes in the form of a flowchart or flow diagram. However,other operations that are not depicted can be incorporated in theexample processes that are schematically illustrated. For example, oneor more additional operations can be performed before, after,simultaneously, or between any of the illustrated operations. In somecircumstances, multitasking and parallel processing may be advantageous.Moreover, the separation of various system components in theimplementations described above should not be understood as requiringsuch separation in all implementations, and it should be understood thatthe described program components and systems can generally be integratedtogether in a single software product or packaged into multiple softwareproducts.

1. A method for wireless communications by a user equipment (UE),comprising: receiving radio resource control (RRC) signaling indicatinga set of cells that support physical (PHY) layer or medium accesscontrol (MAC) layer mobility signaling; receiving at least one downlinkcontrol information (DCI) indicating mobility information for the set ofcells; and updating one or more features of the set of cells based onthe DCI.
 2. The method of claim 1, wherein the set of cells aresupported by one or more distributed units (DUs) under a common centralunit (CU).
 3. The method of claim 2, wherein: the one or more DUscomprises a common DU that supports each cell of the set of cells. 4.The method of claim 1, wherein the DCI indicates at least one of: anidentifier (ID) of a cell of the set of cells to be activated to servethe UE that is not currently in a subset of the set of cells that areactivated for serving the UE; or an ID of one of the cells in the subsetof cells that is to be removed from the subset and de-activated fromserving the UE.
 5. The method of claim 4, wherein the DCI comprises afield that points to the ID of the cell to be activated or deactivatedin a table or list configured by the RRC signaling.
 6. The method ofclaim 1, wherein the DCI indicates an update to System Information (SI)for one or more of the cells in the set.
 7. The method of claim 6,wherein: the RRC signaling configures one or more sets of SI values; andthe DCI indicates the update to SI by at least one of deactivating oractivating one or more of the sets of SI values.
 8. The method of claim6, wherein one or more SI information elements (IEs) eligible forupdating via the DCI occur in a predefined order and are addressed basedon at least one of numbering or a bitmap in the DCI.
 9. The method ofclaim 1, wherein: the RRC signaling indicates one or more sets ofoptions for cells in the set; and the DCI activates one or more sets ofoptions for a cell upon activation.
 10. The method of claim 9, whereinat least some of the options relate to: a timing advance group (TAG)timing advance (TA) information, a measurement configuration, or andupdate or change to a primary cell (PCell).
 11. The method of claim 1,wherein: a format of the DCI depends, at least in part, on a type ortypes of information conveyed.
 12. The method of claim 1, wherein: theat least one DCI comprises at least a first DCI and a second DCI; andthe first DCI indicates a type or types of information provided in thesecond DCI.
 13. The method of claim 1, further comprising transmittingan acknowledgment of the at least one DCI.
 14. A method for wirelesscommunications by a network entity, comprising: sending a user equipment(UE) radio resource control (RRC) signaling indicating a set of cellsthat support physical (PHY) layer or medium access control (MAC) layermobility signaling; sending the UE at least one downlink controlinformation (DCI) indicating mobility information for the set of cells;and communicating with the UE via a subset of the cells that areactivated with one or more features of the set of cells updated based onthe DCI.
 15. The method of claim 14, wherein the set of cells aresupported by one or more distributed units (DUs) under a common centralunit (CU).
 16. The method of claim 15, wherein: the one or more DUscomprises a common DU that supports each cell of the set of cells. 17.The method of claim 14, wherein the DCI indicates at least one of: anidentifier (ID) of a cell of the set of cells to be activated to servethe UE that is not currently in a subset of the set of cells activatedfor serving the UE; or an ID of one of the cells in the subset of cellsthat is to be removed from the subset and de-activated from serving theUE.
 18. The method of claim 17, wherein the DCI comprises a field thatpoints to the ID of the cell to be activated or deactivated in a tableor list configured by the RRC signaling.
 19. The method of claim 14,wherein the DCI indicates an update to System Information (SI) for oneor more of the cells in the set.
 20. An apparatus for wirelesscommunications by a user equipment (UE), comprising: a receiverconfigured to receive radio resource control (RRC) signaling indicatinga set of cells that support physical (PHY) layer or medium accesscontrol (MAC) layer mobility signaling and receive at least one downlinkcontrol information (DCI) indicating mobility information for the set ofcells; and at least one processor configured to update one or morefeatures of the set of cells based on the DCI.